Molding machine



Dec; 14, 1926.

J. A. RATHBONE MOLDING MACHINE Filed March 24 1924 Gite/anew PatentedDec. 14, l il'ifi.

urrsu era JOHN A. nnrnteonn/or DE'IRGIT, MICHIGAN.

MOLDING MACHINE.

Application filed March 24, 1924. Serial No. 701,529.

The invention realtes to molding machines of that type more particularlydesigned for 1 stacked with otl er flasks forming a series-of superposedmold cavities having sprue connections through which the molten metalmay be introduced. 7

With machines of the type just described it is important to have a highspeed of operation in order to increase the output, but it is equallyimportant to preserve the formed molds from injury. Thus during thedrawing of the pattern too great speed may result in breaking the moldsurface and render the mold useless. necessary to retard the downwardmovement of the plunger, which has heretofore been accomplished by theuse of a dash pot. The mold is drawn from the drag pattern with littledifficulty, as said pattern is above, but the drawing of thecope'pattern is a more delicate operation. This is accomplished byarresting movement of the flask during the continued descent of the ramand cope pattern, but, as just stated, the movement must be so retardedas to perform such operation without injury to the mold. Thisnecessarily slows the operation of the machine and increases the lengthof time for each cycle.

It is the object of the present invention to increase the speed andoutput of the machine without any detrimental action and to this end theinvention consists in the means employed for producing a variable speed,which is as high aspossible during the greater part of the movement ofthe ram, but is retarded during the intervals in which the patterns aredrawn. The invention further consists in various features of theconstruction as hereinafter set forth.

In the drawings:

Figure 1 is a sectional front elevation of the machine;

Figure 2 is an enlarged sectional view of a portion of Figure '1.

To avoid such result itis 1n general construction the molding mach ne towhich my improvements are ap plied comprises a base A having r gidcolumns B and B rising therefrom with a swinging head C pivotallymounted at the upper end of the column B anddetachably looking with thecolumn B. D is a cylinder formed centrally of the base A. E is a pistonengaging said cylinder and F the ramming head mounted on said piston.The

head F is provided with a plurality of up wardly extending lugs F forsupporting an annular flask frame G, which in turn is adapted to.receive and support the flask H.

These parts are aligned by pins I projecting upward from the ramminghead and engaging registering apertures in the frame and flask. Withinthe flask frame is arranged an annular vibrator frame J, which in turncarries the supporting plate for the cope I pattern detachably securedthereto. Se-

cured to the swinging head G is an upper ramming head K to which thedrag pattern plate L is attached. This is so arranged as to registerwith the opening in the sand frame and flask and to enter the sameduring the upward movement of the ram.

Beneath the flask frame G and cut away -to avoid the lugs F on the lowerramming head F is a stool plate M. The function of this plate is toseparate the flask frame from the pattern plate and this has heretoforebeen accomplished by engaging supporting lugs with the stool plate so asto completely arrest its movement. Such a construction will affect thedrawing of the pattern from the mold, but, as has been stated, themovement of the ram must be sufficiently slow to avoid injury.

As specifically shown in the drawings, I substitute for the usual meansof completely arresting the stool plate mechanism by which its movementis merely retarded so that the differential will draw the pattern fromthe mold. This mechanism comprises cams N pivotally mounted at oppositeends of the ram having outwardly extending actuating arms N for engagingbearings O mounted on the columns or other stationary part. The cams Nengage roller bearings P mounted in bifurcated outer extensions of thestool plate and the arrangement is such that when the arms l contactwith the bearings U, the camwill be rotated in contact with the rollersP and will gradually separate the pattern from the mold. It will benoted V however, that the stool plate may continue to descend with theram, but that it moves at a slower rate so as to produce the desireddifi'erential.

lVhile- I have described a specific means of producing the differentialmovement, it is obvious that other constructions may be devised for thesame purpose. All that is required is that the velocity of movementseparating the pattern from the mold is less than the normal velocity ofthe ram during its descending movement, so that a greater speed may beimparted to the ram without injury to the mold.

The operation will be understood from the above description, but inbrief is as follows: The ram F is normally at the lower end of itsmovement and to engage the flask and sand frame therewith the cross headC is first swung out to provide the necessary clearance. hen these partsare in position, sand is filled in to the flask and frame and struck oiilevel with the top oi' the frame. Movement is then imparted to thepiston E through suitable pneumatic connections (not described), whichimparts a rapid upward movement to the flask. The velocity is such thatthe inertia of the sand when contacting with the drag pattern will causeit 1 to fill all parts of the pattern and with the further compressionof the ram produce the necessary density. The downward movement of theram is controlled bysuitable means such as the dash pot Q, but a muchmore rapid movement is permitted than with the constructions heretoforeused. Thus the inertia of the parts will retard the acceleration of theram when separating the mold from the drag pattern on the upper ramminghead, and furthermore this operation can be performed at greater speedthan the separation of the cope pattern. Thus the ram will descend quiterapidly, but before it completes its movement the cam N and asso ciatedparts will operate to slowly separate the cope pattern from the mold asufficient distance to break the contact, after which the furtherdescent of all of the parts is at the speed of the ram.

What I claim as my invention is:

1. In a molding machine, the combination with a. reciprocatory ramminghead, a mold flask and a cooperating pattern which is separated from themold during movement of said head, and means for causing a difierentialmovement of said flask and pattern.

2. In a molding machine, the combination with a reciprocatory ramminghead, a mold flask and a pattern, of means for drawing the pattern fromthe mold in said flask during the return movement of said reciprocatoryramming head, and means for dil ferentially moving the flask forretarding the drawing movement relative to the normal velocity of returnmovement of said head.

3. In a molding machine, the coi'i'ibination with a ,recipvocatoryrannning head, a mold flask, a pattern which is separated from the moldin said llask during the return movement of said head, means forcontrolling the velocity of return movement ot said head, andcooperating means for controlling the relative velocity or mold andpattern during separation of the one from the other.

i. In a molding machine, the combination with a reciprocatory ramminghead, a mold flask and a pattern both normally 'arried by said head, ofmeans for drawing the pattern from the mold in said flask during thereturn movement of the head, and means for differentially moving saidflask and head during said drawing movement.

5. In a molding machine, the combination with a reciprocatory ramminghead, a mold flask and a pattern, both normally carried by said head,and means operating during the return movement of said head for movingsaid flask at a velocity less than the normal velocity of returnmovement of said head.

6. In a molding machine, the combination with a reciprocatory iamminghead, a mold flask and a pattern normally carried by sait head, of meansoperating during the return movement of said head for retarding movementor" said flask relative to the velocity of movement of said head andpattern carried thereby to effect a relatively slower draw ing of thepattern.

In testimony whereof I afiii; my signature.

JOHN A. RATHBONE.

